Pipe-tongs



NTTED sTATEs PATENT OFFICE.'

HENRY H. GILMORE, OF BOSTON, MASSACHUSETTS.

PIPE-Tones.

Specification forming part of Letters Patent No. 19,842, dated Apr1 6,181581; Ressued June 12, 1866, No. 2,283'.

The nature of the invention consists in the described method or itsequivalent whereby the slotted part of the tongs is so clamped to thepivot that the strain consequent upon the use of the tongs shall notseparate the jaws by slipping the pivot in the slotted jaw.

To enable those skilled in the art to make and use my invention I willproceed to describe its construction and operation.

Figure l is a side view of a pair of pipe tongs constructed inaccordance with my invention. Fig. 2, is a front view of the same, andFig. 3, is a detail showing the slot and pivot in the hooked jaw.

The hooked jaw (A) Vand straight jaw (B) are constructed in the partswhere the vpipe is grasped in the usual Well known manner and thereforeneed no description here, but the part of (A) through which the pivot(a) passes is slotted and increased in size to compensate for thestrength lost by the slot. The pivot is secured. in (B) so that it canturn therein or so that when (a) is prevented from turning can moveabout (a) as a center. The collar (b) formed on supports (A) which isclamped between and the washer by the nut (a) is flattened Where itpasses through the slot in (A) (see Fig. 3) to prevent the pivot fromturning therein. The inclined plane (e) forms part of (A) or is fixed toit. The Washer (c) under thenut (CZ) is also an inclined plane; aprojection on the under side of (c) fits the sides of the groove in (A)and prevents the washer from turning with the nut.

It will be obvious'from inspection of the drawings that any strain whichtends to separate the two parts of the tongs in the direction of theirlength, or to increase the distance between x) surfaces of (A), and thesteeled edge (a) of (B), must cause the inclined plane of (c) to move onthe inclined plane (e) increasing the distance between the upper surfaceof the collar (b) and the lower surface of the nut. This cannot be donewithout stretching or breaking the pivot (a) by directtensile strain.

The tongs constructed as just described may be set to any desireddistance, between (m and (a), within the range of the instrument.

A substitute for the inclined planes above described may be made byforming teeth or indentations on the upper surface of (A) and the lowersurface of the washer (c) the inclined planes being dispensed Theseteeth would be kept interlocked by the nut (d) g to set the instrumentit would be necessary to slack the nut and adjust the position of thejaws before tightening it. It is evident that the distance of from (a)cannot thus be varied by a less amount than the distance of teeth apartand that the strain which tends to separate (00 x) and (2) in thisconstruction would exert no tensile strain on the pivot but would beexerted on the teeth or indentat-ions described.

Having described my invention what I claim as new therein and desiretosecure by Letters Patent of the United States is:

The combination of an inclined plane or planes or the equivalentthereofy with the slotted jaw, for the purpose described.

HY. H. GILMORE.

Witnesses:

J. B. CROSBY, GORDON MCKAY.

[FIRST PRINTED 1912.]

with.

